1. Field of Invention
The invention relates to a fast networking data device. More particularly, the invention relates to an IEEE 802.3 100BASE-TX FEMR (Fast Ethernet Multiport Repeater).
2. Related Art
The Ethernet is a common communications standard used in an LAN (Local Area Network) for sharing information among computer systems, printers, modems and other data devices. The conventional Ethernet operates at a transmission speed of 10 Mbps. Nowadays, modern networks in the industry have changed to a higher speed: 100 Mbps. However, a wider data transmission bandwidth brings the new problem of message collisions, which strictly limit the area and length of the network.
Both the Ethernet (10 Mbps) and the fast Ethernet (100 Mbps) use an industrial standard method called the CSMA (Carrier Sense Multiple Access) to retrieve data on the network. The CSMA describes how an Ethernet data device detects whether a network line is idle before receiving data from the network.
When two or more devices are transmitting data at the same time, data collisions will occur. To allow the data devices to recover from such situations, the specifications of the Ethernet and the fast Ethernet include a recovery method called the collision detection.
The specifications of the Ethernet or the fast Ethernet limit the length of network lines and the number of repeaters. This is because the network only allows a maximum transmission delay for message packets transmitting from data transmitting-devices to data-receiving devices. Increasing the transmission speed imposes additional limits on the network configuration. Therefore, the network has to have better collision detection ability in order to improve the transmission quality and provide a better network environment.